<!DOCTYPE html>
<html lang="zh-CN">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div class="fa">
        <div class="son"></div>
    </div>


    <script>
        document.addEventListener('click', function () {
            alert('哈哈')
        })
        fa.addEventListener('click', function () {
            alert('fa')
        })
        son.addEventListener('click', function (e) {
            alert('son')
            //  阻止流动传播  要添加事件对象
            e.stopPropagate()
        })
    </script>
</body>

</html>